Now that we no longer refer to mod->arch.ftrace_trampolines in the body
of ftrace_make_call(), we can use IS_ENABLED() rather than ifdeffery,
and make the code easier to follow. Likewise in ftrace_make_nop().

Let's do so.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>

This patch implements FTRACE_WITH_REGS for arm64, which allows a traced
function's arguments (and some other registers) to be captured into a
struct pt_regs, allowing these to be inspected and/or modified. This is
a building block for live-patching, where a function's arguments may be
forwarded to another function. This is also necessary to enable ftrace
and in-kernel pointer authentication at the same time, as it allows the
LR value to be captured and adjusted prior to signing.

Using GCC's -fpatchable-function-entry=N option, we can have the
compiler insert a configurable number of NOPs between the function entry
point and the usual prologue. This also ensures functions are AAPCS
compliant (e.g. disabling inter-procedural register allocation).

For example, with -fpatchable-function-entry=2, GCC 8.1.0 compiles the
following:

| unsigned long bar(void);
|
| unsigned long foo(void)
| {
|         return bar() + 1;
| }

... to:

| <foo>:
|         nop
|         nop
|         stp     x29, x30, [sp, #-16]!
|         mov     x29, sp
|         bl      0 <bar>
|         add     x0, x0, #0x1
|         ldp     x29, x30, [sp], #16
|         ret

This patch builds the kernel with -fpatchable-function-entry=2,
prefixing each function with two NOPs. To trace a function, we replace
these NOPs with a sequence that saves the LR into a GPR, then calls an
ftrace entry assembly function which saves this and other relevant
registers:

| mov	x9, x30
| bl	<ftrace-entry>

Since patchable functions are AAPCS compliant (and the kernel does not
use x18 as a platform register), x9-x18 can be safely clobbered in the
patched sequence and the ftrace entry code.

There are now two ftrace entry functions, ftrace_regs_entry (which saves
all GPRs), and ftrace_entry (which saves the bare minimum). A PLT is
allocated for each within modules.
Signed-off-by: Torsten Duwe <duwe@suse.de>
[Mark: rework asm, comments, PLTs, initialization, commit message]
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: AKASHI Takahiro <takahiro.akashi@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Josh Poimboeuf <jpoimboe@redhat.com>
Cc: Julien Thierry <jthierry@redhat.com>
Cc: Will Deacon <will@kernel.org>

So that assembly code can more easily manipulate the FP (x29) within a
pt_regs, add an S_FP asm-offsets definition.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>

For FTRACE_WITH_REGS, we're going to want to generate a MOV (register)
instruction as part of the callsite intialization. As MOV (register) is
an alias for ORR (shifted register), we can generate this with
aarch64_insn_gen_logical_shifted_reg(), but it's somewhat verbose and
difficult to read in-context.

Add a aarch64_insn_gen_move_reg() wrapper for this case so that we can
write callers in a more straightforward way.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>

Currently we lazily-initialize a module's ftrace PLT at runtime when we
install the first ftrace call. To do so we have to apply a number of
sanity checks, transiently mark the module text as RW, and perform an
IPI as part of handling Neoverse-N1 erratum #1542419.

We only expect the ftrace trampoline to point at ftrace_caller() (AKA
FTRACE_ADDR), so let's simplify all of this by intializing the PLT at
module load time, before the module loader marks the module RO and
performs the intial I-cache maintenance for the module.

Thus we can rely on the module having been correctly intialized, and can
simplify the runtime work necessary to install an ftrace call in a
module. This will also allow for the removal of module_disable_ro().

Tested by forcing ftrace_make_call() to use the module PLT, and then
loading up a module after setting up ftrace with:

| echo ":mod:<module-name>" > set_ftrace_filter;
| echo function > current_tracer;
| modprobe <module-name>

Since FTRACE_ADDR is only defined when CONFIG_DYNAMIC_FTRACE is
selected, we wrap its use along with most of module_init_ftrace_plt()
with ifdeffery rather than using IS_ENABLED().
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Will Deacon <will@kernel.org>

When we load a module, we have to perform some special work for a couple
of named sections. To do this, we iterate over all of the module's
sections, and perform work for each section we recognize.

To make it easier to handle the unexpected absence of a section, and to
make the section-specific logic easer to read, let's factor the section
search into a helper. Similar is already done in the core module loader,
and other architectures (and ideally we'd unify these in future).

If we expect a module to have an ftrace trampoline section, but it
doesn't have one, we'll now reject loading the module. When
ARM64_MODULE_PLTS is selected, any correctly built module should have
one (and this is assumed by arm64's ftrace PLT code) and the absence of
such a section implies something has gone wrong at build time.

Subsequent patches will make use of the new helper.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: James Morse <james.morse@arm.com>
Cc: Will Deacon <will@kernel.org>

When using patchable-function-entry, the compiler will record the
callsites into a section named "__patchable_function_entries" rather
than "__mcount_loc". Let's abstract this difference behind a new
FTRACE_CALLSITE_SECTION, so that architectures don't have to handle this
explicitly (e.g. with custom module linker scripts).

As parisc currently handles this explicitly, it is fixed up accordingly,
with its custom linker script removed. Since FTRACE_CALLSITE_SECTION is
only defined when DYNAMIC_FTRACE is selected, the parisc module loading
code is updated to only use the definition in that case. When
DYNAMIC_FTRACE is not selected, modules shouldn't have this section, so
this removes some redundant work in that case.

To make sure that this is keep up-to-date for modules and the main
kernel, a comment is added to vmlinux.lds.h, with the existing ifdeffery
simplified for legibility.

I built parisc generic-{32,64}bit_defconfig with DYNAMIC_FTRACE enabled,
and verified that the section made it into the .ko files for modules.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Acked-by: Helge Deller <deller@gmx.de>
Acked-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Sven Schnelle <svens@stackframe.org>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: James E.J. Bottomley <James.Bottomley@HansenPartnership.com>
Cc: Jessica Yu <jeyu@kernel.org>
Cc: linux-parisc@vger.kernel.org

Architectures may need to perform special initialization of ftrace
callsites, and today they do so by special-casing ftrace_make_nop() when
the expected branch address is MCOUNT_ADDR. In some cases (e.g. for
patchable-function-entry), we don't have an mcount-like symbol and don't
want a synthetic MCOUNT_ADDR, but we may need to perform some
initialization of callsites.

To make it possible to separate initialization from runtime
modification, and to handle cases without an mcount-like symbol, this
patch adds an optional ftrace_init_nop() function that architectures can
implement, which does not pass a branch address.

Where an architecture does not provide ftrace_init_nop(), we will fall
back to the existing behaviour of calling ftrace_make_nop() with
MCOUNT_ADDR.

At the same time, ftrace_code_disable() is renamed to
ftrace_nop_initialize() to make it clearer that it is intended to
intialize a callsite into a disabled state, and is not for disabling a
callsite that has been runtime enabled. The kerneldoc description of rec
arguments is updated to cover non-mcount callsites.
Signed-off-by: Mark Rutland <mark.rutland@arm.com>
Reviewed-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Reviewed-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Reviewed-by: Miroslav Benes <mbenes@suse.cz>
Reviewed-by: Steven Rostedt (VMware) <rostedt@goodmis.org>
Reviewed-by: Torsten Duwe <duwe@suse.de>
Tested-by: Amit Daniel Kachhap <amit.kachhap@arm.com>
Tested-by: Sven Schnelle <svens@stackframe.org>
Tested-by: Torsten Duwe <duwe@suse.de>
Cc: Ingo Molnar <mingo@redhat.com>

Pull tracing fixes from Steven Rostedt:
 "A few tracing fixes:

   - Remove lockdown from tracefs itself and moved it to the trace
     directory. Have the open functions there do the lockdown checks.

   - Fix a few races with opening an instance file and the instance
     being deleted (Discovered during the lockdown updates). Kept
     separate from the clean up code such that they can be backported to
     stable easier.

   - Clean up and consolidated the checks done when opening a trace
     file, as there were multiple checks that need to be done, and it
     did not make sense having them done in each open instance.

   - Fix a regression in the record mcount code.

   - Small hw_lat detector tracer fixes.

   - A trace_pipe read fix due to not initializing trace_seq"

* tag 'trace-v5.4-rc2' of git://git.kernel.org/pub/scm/linux/kernel/git/rostedt/linux-trace:
  tracing: Initialize iter->seq after zeroing in tracing_read_pipe()
  tracing/hwlat: Don't ignore outer-loop duration when calculating max_latency
  tracing/hwlat: Report total time spent in all NMIs during the sample
  recordmcount: Fix nop_mcount() function
  tracing: Do not create tracefs files if tracefs lockdown is in effect
  tracing: Add locked_down checks to the open calls of files created for tracefs
  tracing: Add tracing_check_open_get_tr()
  tracing: Have trace events system open call tracing_open_generic_tr()
  tracing: Get trace_array reference for available_tracers files
  ftrace: Get a reference counter for the trace_array on filter files
  tracefs: Revert ccbd54ff ("tracefs: Restrict tracefs when the kernel is locked down")

Merge tag 'hwmon-for-v5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging

Pull hwmon fixes from Guenter Roeck:

 - Update/fix inspur-ipsps1 and k10temp Documentation

 - Fix nct7904 driver

 - Fix HWMON_P_MIN_ALARM mask in hwmon core

* tag 'hwmon-for-v5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/groeck/linux-staging:
  hwmon: docs: Extend inspur-ipsps1 title underline
  hwmon: (nct7904) Add array fan_alarm and vsen_alarm to store the alarms in nct7904_data struct.
  docs: hwmon: Include 'inspur-ipsps1.rst' into docs
  hwmon: Fix HWMON_P_MIN_ALARM mask
  hwmon: (k10temp) Update documentation and add temp2_input info
  hwmon: (nct7904) Fix the incorrect value of vsen_mask in nct7904_data struct

Pull MTD fixes from Richard Weinberger:
 "Two fixes for MTD:

   - spi-nor: Fix for a regression in write_sr()

   - rawnand: Regression fix for the au1550nd driver"

* tag 'fixes-for-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/mtd/linux:
  mtd: rawnand: au1550nd: Fix au_read_buf16() prototype
  mtd: spi-nor: Fix direction of the write_sr() transfer

Pull io_uring fix from Jens Axboe:
 "Single small fix for a regression in the sequence logic for linked
  commands"

* tag 'for-linus-20191012' of git://git.kernel.dk/linux-block:
  io_uring: fix sequence logic for timeout requests

A customer reported the following softlockup:

[899688.160002] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [test.sh:16464]
[899688.160002] CPU: 0 PID: 16464 Comm: test.sh Not tainted 4.12.14-6.23-azure #1 SLE12-SP4
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] Kernel panic - not syncing: softlockup: hung tasks
[899688.160002] RIP: 0010:up_write+0x1a/0x30
[899688.160002] RSP: 0018:ffffa86784d4fde8 EFLAGS: 00000257 ORIG_RAX: ffffffffffffff12
[899688.160002] RAX: ffffffff970fea00 RBX: 0000000000000001 RCX: 0000000000000000
[899688.160002] RDX: ffffffff00000001 RSI: 0000000000000080 RDI: ffffffff970fea00
[899688.160002] RBP: ffffffffffffffff R08: ffffffffffffffff R09: 0000000000000000
[899688.160002] R10: 0000000000000000 R11: 0000000000000000 R12: ffff8b59014720d8
[899688.160002] R13: ffff8b59014720c0 R14: ffff8b5901471090 R15: ffff8b5901470000
[899688.160002]  tracing_read_pipe+0x336/0x3c0
[899688.160002]  __vfs_read+0x26/0x140
[899688.160002]  vfs_read+0x87/0x130
[899688.160002]  SyS_read+0x42/0x90
[899688.160002]  do_syscall_64+0x74/0x160

It caught the process in the middle of trace_access_unlock(). There is
no loop. So, it must be looping in the caller tracing_read_pipe()
via the "waitagain" label.

Crashdump analyze uncovered that iter->seq was completely zeroed
at this point, including iter->seq.seq.size. It means that
print_trace_line() was never able to print anything and
there was no forward progress.

The culprit seems to be in the code:

	/* reset all but tr, trace, and overruns */
	memset(&iter->seq, 0,
	       sizeof(struct trace_iterator) -
	       offsetof(struct trace_iterator, seq));

It was added by the commit 53d0aa77 ("ftrace:
add logic to record overruns"). It was v2.6.27-rc1.
It was the time when iter->seq looked like:

     struct trace_seq {
	unsigned char		buffer[PAGE_SIZE];
	unsigned int		len;
     };

There was no "size" variable and zeroing was perfectly fine.

The solution is to reinitialize the structure after or without
zeroing.

Link: http://lkml.kernel.org/r/20191011142134.11997-1-pmladek@suse.comSigned-off-by: Petr Mladek <pmladek@suse.com>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

max_latency is intended to record the maximum ever observed hardware
latency, which may occur in either part of the loop (inner/outer). So
we need to also consider the outer-loop sample when updating
max_latency.

Link: http://lkml.kernel.org/r/157073345463.17189.18124025522664682811.stgit@srivatsa-ubuntu

Fixes: e7c15cd8 ("tracing: Added hardware latency tracer")
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

nmi_total_ts is supposed to record the total time spent in *all* NMIs
that occur on the given CPU during the (active portion of the)
sampling window. However, the code seems to be overwriting this
variable for each NMI, thereby only recording the time spent in the
most recent NMI. Fix it by accumulating the duration instead.

Link: http://lkml.kernel.org/r/157073343544.17189.13911783866738671133.stgit@srivatsa-ubuntu

Fixes: 7b2c8625 ("tracing: Add NMI tracing in hwlat detector")
Cc: stable@vger.kernel.org
Signed-off-by: Srivatsa S. Bhat (VMware) <srivatsa@csail.mit.edu>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The removal of the longjmp code in recordmcount.c mistakenly made the return
of make_nop() being negative an exit of nop_mcount(). It should not exit the
routine, but instead just not process that part of the code. By exiting with
an error code, it would cause the update of recordmcount to fail some files
which would fail the build if ftrace function tracing was enabled.

Link: http://lkml.kernel.org/r/20191009110538.5909fec6@gandalf.local.homeReported-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Tested-by: Uwe Kleine-König <u.kleine-koenig@pengutronix.de>
Fixes: 3f1df120 ("recordmcount: Rewrite error/success handling")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

If on boot up, lockdown is activated for tracefs, don't even bother creating
the files. This can also prevent instances from being created if lockdown is
in effect.

Link: http://lkml.kernel.org/r/CAHk-=whC6Ji=fWnjh2+eS4b15TnbsS4VPVtvBOwCy1jjEG_JHQ@mail.gmail.comSuggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Added various checks on open tracefs calls to see if tracefs is in lockdown
mode, and if so, to return -EPERM.

Note, the event format files (which are basically standard on all machines)
as well as the enabled_functions file (which shows what is currently being
traced) are not lockde down. Perhaps they should be, but it seems counter
intuitive to lockdown information to help you know if the system has been
modified.

Link: http://lkml.kernel.org/r/CAHk-=wj7fGPKUspr579Cii-w_y60PtRaiDgKuxVtBAMK0VNNkA@mail.gmail.comSuggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Currently, most files in the tracefs directory test if tracing_disabled is
set. If so, it should return -ENODEV. The tracing_disabled is called when
tracing is found to be broken. Originally it was done in case the ring
buffer was found to be corrupted, and we wanted to prevent reading it from
crashing the kernel. But it's also called if a tracing selftest fails on
boot. It's a one way switch. That is, once it is triggered, tracing is
disabled until reboot.

As most tracefs files can also be used by instances in the tracefs
directory, they need to be carefully done. Each instance has a trace_array
associated to it, and when the instance is removed, the trace_array is
freed. But if an instance is opened with a reference to the trace_array,
then it requires looking up the trace_array to get its ref counter (as there
could be a race with it being deleted and the open itself). Once it is
found, a reference is added to prevent the instance from being removed (and
the trace_array associated with it freed).

Combine the two checks (tracing_disabled and trace_array_get()) into a
single helper function. This will also make it easier to add lockdown to
tracefs later.

Link: http://lkml.kernel.org/r/20191011135458.7399da44@gandalf.local.homeSigned-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Instead of having the trace events system open call open code the taking of
the trace_array descriptor (with trace_array_get()) and then calling
trace_open_generic(), have it use the tracing_open_generic_tr() that does
the combination of the two. This requires making tracing_open_generic_tr()
global.
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

As instances may have different tracers available, we need to look at the
trace_array descriptor that shows the list of the available tracers for the
instance. But there's a race between opening the file and an admin
deleting the instance. The trace_array_get() needs to be called before
accessing the trace_array.

Cc: stable@vger.kernel.org
Fixes: 607e2ea1 ("tracing: Set up infrastructure to allow tracers for instances")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

The ftrace set_ftrace_filter and set_ftrace_notrace files are specific for
an instance now. They need to take a reference to the instance otherwise
there could be a race between accessing the files and deleting the instance.

It wasn't until the :mod: caching where these file operations started
referencing the trace_array directly.

Cc: stable@vger.kernel.org
Fixes: 673feb9d ("ftrace: Add :mod: caching infrastructure to trace_array")
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Running the latest kernel through my "make instances" stress tests, I
triggered the following bug (with KASAN and kmemleak enabled):

mkdir invoked oom-killer:
gfp_mask=0x40cd0(GFP_KERNEL|__GFP_COMP|__GFP_RECLAIMABLE), order=0,
oom_score_adj=0
CPU: 1 PID: 2229 Comm: mkdir Not tainted 5.4.0-rc2-test #325
Hardware name: MSI MS-7823/CSM-H87M-G43 (MS-7823), BIOS V1.6 02/22/2014
Call Trace:
 dump_stack+0x64/0x8c
 dump_header+0x43/0x3b7
 ? trace_hardirqs_on+0x48/0x4a
 oom_kill_process+0x68/0x2d5
 out_of_memory+0x2aa/0x2d0
 __alloc_pages_nodemask+0x96d/0xb67
 __alloc_pages_node+0x19/0x1e
 alloc_slab_page+0x17/0x45
 new_slab+0xd0/0x234
 ___slab_alloc.constprop.86+0x18f/0x336
 ? alloc_inode+0x2c/0x74
 ? irq_trace+0x12/0x1e
 ? tracer_hardirqs_off+0x1d/0xd7
 ? __slab_alloc.constprop.85+0x21/0x53
 __slab_alloc.constprop.85+0x31/0x53
 ? __slab_alloc.constprop.85+0x31/0x53
 ? alloc_inode+0x2c/0x74
 kmem_cache_alloc+0x50/0x179
 ? alloc_inode+0x2c/0x74
 alloc_inode+0x2c/0x74
 new_inode_pseudo+0xf/0x48
 new_inode+0x15/0x25
 tracefs_get_inode+0x23/0x7c
 ? lookup_one_len+0x54/0x6c
 tracefs_create_file+0x53/0x11d
 trace_create_file+0x15/0x33
 event_create_dir+0x2a3/0x34b
 __trace_add_new_event+0x1c/0x26
 event_trace_add_tracer+0x56/0x86
 trace_array_create+0x13e/0x1e1
 instance_mkdir+0x8/0x17
 tracefs_syscall_mkdir+0x39/0x50
 ? get_dname+0x31/0x31
 vfs_mkdir+0x78/0xa3
 do_mkdirat+0x71/0xb0
 sys_mkdir+0x19/0x1b
 do_fast_syscall_32+0xb0/0xed

I bisected this down to the addition of the proxy_ops into tracefs for
lockdown. It appears that the allocation of the proxy_ops and then freeing
it in the destroy_inode callback, is causing havoc with the memory system.
Reading the documentation about destroy_inode and talking with Linus about
this, this is buggy and wrong. When defining the destroy_inode() method, it
is expected that the destroy_inode() will also free the inode, and not just
the extra allocations done in the creation of the inode. The faulty commit
causes a memory leak of the inode data structure when they are deleted.

Instead of allocating the proxy_ops (and then having to free it) the checks
should be done by the open functions themselves, and not hack into the
tracefs directory. First revert the tracefs updates for locked_down and then
later we can add the locked_down checks in the kernel/trace files.

Link: http://lkml.kernel.org/r/20191011135458.7399da44@gandalf.local.home

Fixes: ccbd54ff ("tracefs: Restrict tracefs when the kernel is locked down")
Suggested-by: Linus Torvalds <torvalds@linux-foundation.org>
Signed-off-by: Steven Rostedt (VMware) <rostedt@goodmis.org>

Pull char/misc driver fixes from Greg KH:
 "Here are some small char/misc driver fixes for 5.4-rc3.

  Nothing huge here. Some binder driver fixes (although it is still
  being discussed if these all fix the reported issues or not, so more
  might be coming later), some mei device ids and fixes, and a google
  firmware driver bugfix that fixes a regression, as well as some other
  tiny fixes.

  All have been in linux-next with no reported issues"

* tag 'char-misc-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/char-misc:
  firmware: google: increment VPD key_len properly
  w1: ds250x: Fix build error without CRC16
  virt: vbox: fix memory leak in hgcm_call_preprocess_linaddr
  binder: Fix comment headers on binder_alloc_prepare_to_free()
  binder: prevent UAF read in print_binder_transaction_log_entry()
  misc: fastrpc: prevent memory leak in fastrpc_dma_buf_attach
  mei: avoid FW version request on Ibex Peak and earlier
  mei: me: add comet point (lake) LP device ids

Pull staging/IIO driver fixes from Greg KH:
 "Here are some staging and IIO driver fixes for 5.4-rc3.

  The "biggest" thing here is a removal of the fbtft device and flexfb
  code as they have been abandoned by their authors and are no longer
  needed for that hardware.

  Other than that, the usual amount of staging driver and iio driver
  fixes for reported issues, and some speakup sysfs file documentation,
  which has been long awaited for.

  All have been in linux-next with no reported issues"

* tag 'staging-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/staging: (32 commits)
  iio: Fix an undefied reference error in noa1305_probe
  iio: light: opt3001: fix mutex unlock race
  iio: adc: ad799x: fix probe error handling
  iio: light: add missing vcnl4040 of_compatible
  iio: light: fix vcnl4000 devicetree hooks
  iio: imu: st_lsm6dsx: fix waitime for st_lsm6dsx i2c controller
  iio: adc: axp288: Override TS pin bias current for some models
  iio: imu: adis16400: fix memory leak
  iio: imu: adis16400: release allocated memory on failure
  iio: adc: stm32-adc: fix a race when using several adcs with dma and irq
  iio: adc: stm32-adc: move registers definitions
  iio: accel: adxl372: Perform a reset at start up
  iio: accel: adxl372: Fix push to buffers lost samples
  iio: accel: adxl372: Fix/remove limitation for FIFO samples
  iio: adc: hx711: fix bug in sampling of data
  staging: vt6655: Fix memory leak in vt6655_probe
  staging: exfat: Use kvzalloc() instead of kzalloc() for exfat_sb_info
  Staging: fbtft: fix memory leak in fbtft_framebuffer_alloc
  staging: speakup: document sysfs attributes
  staging: rtl8188eu: fix HighestRate check in odm_ARFBRefresh_8188E()
  ...

Pull tty/serial driver fixes from Greg KH:
 "Here are some small tty and serial driver fixes for 5.4-rc3 that
  resolve a number of reported issues and regressions.

  None of these are huge, full details are in the shortlog. There's also
  a MAINTAINERS update that I think you might have already taken in your
  tree already, but git should handle that merge easily.

  All have been in linux-next with no reported issues"

* tag 'tty-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/tty:
  MAINTAINERS: kgdb: Add myself as a reviewer for kgdb/kdb
  tty: serial: imx: Use platform_get_irq_optional() for optional IRQs
  serial: fix kernel-doc warning in comments
  serial: 8250_omap: Fix gpio check for auto RTS/CTS
  serial: mctrl_gpio: Check for NULL pointer
  tty: serial: fsl_lpuart: Fix lpuart_flush_buffer()
  tty: serial: Fix PORT_LINFLEXUART definition
  tty: n_hdlc: fix build on SPARC
  serial: uartps: Fix uartps_major handling
  serial: uartlite: fix exit path null pointer
  tty: serial: linflexuart: Fix magic SysRq handling
  serial: sh-sci: Use platform_get_irq_optional() for optional interrupts
  dt-bindings: serial: sh-sci: Document r8a774b1 bindings
  serial/sifive: select SERIAL_EARLYCON
  tty: serial: rda: Fix the link time qualifier of 'rda_uart_exit()'
  tty: serial: owl: Fix the link time qualifier of 'owl_uart_exit()'

Pull USB fixes from Greg KH:
 "Here are a lot of small USB driver fixes for 5.4-rc3.

  syzbot has stepped up its testing of the USB driver stack, now able to
  trigger fun race conditions between disconnect and probe functions.
  Because of that we have a lot of fixes in here from Johan and others
  fixing these reported issues that have been around since almost all
  time.

  We also are just deleting the rio500 driver, making all of the syzbot
  bugs found in it moot as it turns out no one has been using it for
  years as there is a userspace version that is being used instead.

  There are also a number of other small fixes in here, all resolving
  reported issues or regressions.

  All have been in linux-next without any reported issues"

* tag 'usb-5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/gregkh/usb: (65 commits)
  USB: yurex: fix NULL-derefs on disconnect
  USB: iowarrior: use pr_err()
  USB: iowarrior: drop redundant iowarrior mutex
  USB: iowarrior: drop redundant disconnect mutex
  USB: iowarrior: fix use-after-free after driver unbind
  USB: iowarrior: fix use-after-free on release
  USB: iowarrior: fix use-after-free on disconnect
  USB: chaoskey: fix use-after-free on release
  USB: adutux: fix use-after-free on release
  USB: ldusb: fix NULL-derefs on driver unbind
  USB: legousbtower: fix use-after-free on release
  usb: cdns3: Fix for incorrect DMA mask.
  usb: cdns3: fix cdns3_core_init_role()
  usb: cdns3: gadget: Fix full-speed mode
  USB: usb-skeleton: drop redundant in-urb check
  USB: usb-skeleton: fix use-after-free after driver unbind
  USB: usb-skeleton: fix NULL-deref on disconnect
  usb:cdns3: Fix for CV CH9 running with g_zero driver.
  usb: dwc3: Remove dev_err() on platform_get_irq() failure
  usb: dwc3: Switch to platform_get_irq_byname_optional()
  ...

Pull scheduler fixes from Ingo Molnar:
 "Two fixes: a guest-cputime accounting fix, and a cgroup bandwidth
  quota precision fix"

* 'sched-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  sched/vtime: Fix guest/system mis-accounting on task switch
  sched/fair: Scale bandwidth quota and period without losing quota/period ratio precision

Pull perf fixes from Ingo Molnar:
 "Mostly tooling fixes, but also a couple of updates for new Intel
  models (which are technically hw-enablement, but to users it's a fix
  to perf behavior on those new CPUs - hope this is fine), an AUX
  inheritance fix, event time-sharing fix, and a fix for lost non-perf
  NMI events on AMD systems"

* 'perf-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (36 commits)
  perf/x86/cstate: Add Tiger Lake CPU support
  perf/x86/msr: Add Tiger Lake CPU support
  perf/x86/intel: Add Tiger Lake CPU support
  perf/x86/cstate: Update C-state counters for Ice Lake
  perf/x86/msr: Add new CPU model numbers for Ice Lake
  perf/x86/cstate: Add Comet Lake CPU support
  perf/x86/msr: Add Comet Lake CPU support
  perf/x86/intel: Add Comet Lake CPU support
  perf/x86/amd: Change/fix NMI latency mitigation to use a timestamp
  perf/core: Fix corner case in perf_rotate_context()
  perf/core: Rework memory accounting in perf_mmap()
  perf/core: Fix inheritance of aux_output groups
  perf annotate: Don't return -1 for error when doing BPF disassembly
  perf annotate: Return appropriate error code for allocation failures
  perf annotate: Fix arch specific ->init() failure errors
  perf annotate: Propagate the symbol__annotate() error return
  perf annotate: Fix the signedness of failure returns
  perf annotate: Propagate perf_env__arch() error
  perf evsel: Fall back to global 'perf_env' in perf_evsel__env()
  perf tools: Propagate get_cpuid() error
  ...

Pull EFI fixes from Ingo Molnar:
 "Misc EFI fixes all across the map: CPER error report fixes, fixes to
  TPM event log parsing, fix for a kexec hang, a Sparse fix and other
  fixes"

* 'efi-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  efi/tpm: Fix sanity check of unsigned tbl_size being less than zero
  efi/x86: Do not clean dummy variable in kexec path
  efi: Make unexported efi_rci2_sysfs_init() static
  efi/tpm: Only set 'efi_tpm_final_log_size' after successful event log parsing
  efi/tpm: Don't traverse an event log with no events
  efi/tpm: Don't access event->count when it isn't mapped
  efivar/ssdt: Don't iterate over EFI vars if no SSDT override was specified
  efi/cper: Fix endianness of PCIe class code

Pull x86 fixes from Ingo Molnar:
 "A handful of fixes: a kexec linking fix, an AMD MWAITX fix, a vmware
  guest support fix when built under Clang, and new CPU model number
  definitions"

* 'x86-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86/cpu: Add Comet Lake to the Intel CPU models header
  lib/string: Make memzero_explicit() inline instead of external
  x86/cpu/vmware: Use the full form of INL in VMWARE_PORT
  x86/asm: Fix MWAITX C-state hint value

Pull x86 license tag fixlets from Ingo Molnar:
 "Fix a couple of SPDX tags in x86 headers to follow the canonical
  pattern"

* 'core-urgent-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip:
  x86: Use the correct SPDX License Identifier in headers

Pull RISC-V fixes from Paul Walmsley:

 - Fix several bugs in the breakpoint trap handler

 - Drop an unnecessary loop around calls to preempt_schedule_irq()

* tag 'riscv/for-v5.4-rc3' of git://git.kernel.org/pub/scm/linux/kernel/git/riscv/linux:
  RISC-V: entry: Remove unneeded need_resched() loop
  riscv: Correct the handling of unexpected ebreak in do_trap_break()
  riscv: avoid sending a SIGTRAP to a user thread trapped in WARN()
  riscv: avoid kernel hangs when trapped in BUG()

Pull MIPS fixes from Paul Burton:

 - Build fixes for CONFIG_OPTIMIZE_INLINING=y builds in which the
   compiler may choose not to inline __xchg() & __cmpxchg().

 - A build fix for Loongson configurations with GCC 9.x.

 - Expose some extra HWCAP bits to indicate support for various
   instruction set extensions to userland.

 - Fix bad stack access in firmware handling code for old SNI
   RM200/300/400 machines.

* tag 'mips_fixes_5.4_2' of git://git.kernel.org/pub/scm/linux/kernel/git/mips/linux:
  MIPS: Disable Loongson MMI instructions for kernel build
  MIPS: elf_hwcap: Export userspace ASEs
  MIPS: fw: sni: Fix out of bounds init of o32 stack
  MIPS: include: Mark __xchg as __always_inline
  MIPS: include: Mark __cmpxchg as __always_inline

Pull powerpc fixes from Michael Ellerman:
 "Fix a kernel crash in spufs_create_root() on Cell machines, since the
  new mount API went in.

  Fix a regression in our KVM code caused by our recent PCR changes.

  Avoid a warning message about a failing hypervisor API on systems that
  don't have that API.

  A couple of minor build fixes.

  Thanks to: Alexey Kardashevskiy, Alistair Popple, Desnes A. Nunes do
  Rosario, Emmanuel Nicolet, Jordan Niethe, Laurent Dufour, Stephen
  Rothwell"

* tag 'powerpc-5.4-3' of git://git.kernel.org/pub/scm/linux/kernel/git/powerpc/linux:
  spufs: fix a crash in spufs_create_root()
  powerpc/kvm: Fix kvmppc_vcore->in_guest value in kvmhv_switch_to_host
  selftests/powerpc: Fix compile error on tlbie_test due to newer gcc
  powerpc/pseries: Remove confusing warning message.
  powerpc/64s/radix: Fix build failure with RADIX_MMU=n

Pull xen fixes from Juergen Gross:

 - correct panic handling when running as a Xen guest

 - cleanup the Xen grant driver to remove printing a pointer being
   always NULL

 - remove a soon to be wrong call of of_dma_configure()

* tag 'for-linus-5.4-rc3-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/xen/tip:
  xen: Stop abusing DT of_dma_configure API
  xen/grant-table: remove unnecessary printing
  x86/xen: Return from panic notifier

Pull s390 fixes from Vasily Gorbik:

 - Fix virtio-ccw DMA regression

 - Fix compiler warnings in uaccess

* tag 's390-5.4-4' of git://git.kernel.org/pub/scm/linux/kernel/git/s390/linux:
  s390/uaccess: avoid (false positive) compiler warnings
  s390/cio: fix virtio-ccw DMA without PV

Tiger Lake is the followon to Ice Lake. From the perspective of Intel
cstate residency counters, there is nothing changed compared with
Ice Lake.

Share icl_cstates with Ice Lake.
Update the comments for Tiger Lake.

The External Design Specification (EDS) is not published yet. It comes
from an authoritative internal source.

The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-10-git-send-email-kan.liang@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>

Tiger Lake is the followon to Ice Lake. PPERF and SMI_COUNT MSRs are
also supported.

The External Design Specification (EDS) is not published yet. It comes
from an authoritative internal source.

The patch has been tested on real hardware.
Signed-off-by: Kan Liang <kan.liang@linux.intel.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: https://lkml.kernel.org/r/1570549810-25049-9-git-send-email-kan.liang@linux.intel.comSigned-off-by: Ingo Molnar <mingo@kernel.org>